This circuit, found in EDN documentation from the 90's, implements a clamp without signal deformation. The integrated circuit is from that time, uncommon nowadays.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...